Center punch



May 23, 1944- I 3. K. TQWNSEND, JR., ET A1. 2,349,567

CENTER PUNCH Filed Nov. 19, 194? 2 Sheets-Sheet 1 liv ay 23, E944. v G. K. ToWNsEND, JR., ll-:T Al. 349,567

CENTER PUNCH Filed Nov. 19, 1942 2 Sheets-Sheet 2 Inventor ww' "flmflwhl,

atented May 23, 1944 N+ eem CENTER PUNCH `George K. Townsend, Jr.,and Jack K. 'Ianiyama,` `A

Honolulu, Territory of H awai Appueauen November 19, 1942, serial No. 466,230

(o1. .aa- 189) l Claim.

The present invention relates to new and useful improvements in center punches, and has for its primary object to provide, in a manner as hereinafter set forth, a tool of this character comprising novel means whereby the indentaticns may be rapidly but accurately made in the desired places in the work.

Another very important object of the invention is to provide a center punch of the aforementioned character embodying a construction and arrangement which is such that the various parts may be expeditiously replaced when necessary.

Other objects of the invention are to provide a center punch of the character described which will be comparatively simple in construction, strong, durable, highly efficient and reliable in use, compact, light in weight, and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specication, taken in connection with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure 1 is a top plan view of a center punch constructed in accordance with the present invention, showing the device in use.

Figure 2 is an elevational view thereof.

Figure 3 is a view in vertical section through the tool, taken substantially on the line 3-3 of Figure 1.

Figure 4 is a top plan view, showing the device folded.

Figure 5 is an elevational view of the folded tool.

Figure 6 is a top plan View of the adjustable arm.

Figure '7 is a view in longitudinal section through the arm.

Figure 8 is a view in longitudinal section through the guide bar.

Figure 9 is a detail view in elevation of the punch housing.

Figure 10 is a detail View in elevation of the punch.

Figure 11 is a detail view principally in vertical section through the thumb screw.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a guide bar I of suitable metal, said guide bar being of hollow construction. In one end portion, the guide bar I has formed transversely therein a groove 2. A threaded opening 3 communicates with the groove 2. Forwardly of the groove 2, the guide bar I further includes a thickened or raised end portion 4 having a segmental recess 5 therein.

Pivotally and slidably mounted on the guide bar I is a graduated arm 6 having a longitudinal slot 'I therein. The slot 1 accommodates a thumb screw 8 which is threaded into the opening 3 for releasably securing the arm 6 in position on the bar I. When in operative position at right angles to the bar I, the arm 6 is engaged in the groove 2, as illustrated to advantage in Figures 1 and 3 of the drawings. Of course, the thumb screw B frictionally secures the arm 6 in adjusted position in the groove 2. When the tool is not in use, the arm 6, after the thumb screw 8 has been sufliciently loosened, is raised out of the groove 2 and swung to a position parallel with the bar I, as seen in Figures 4 and 5 0f the drawings. In this position. the rounded end 9 of the arm 6 is engaged in the recess 5 and the thumb screw 8 is again tightened.

Formed integrally with the other end of the arm 6 is a laterally offset head I0 in the form of a disk. The head Ill has formed therein a smooth opening I I, the center of which is aligned with the adjacent longitudinal edge of the arm E. Rising from the head I0 is an internally threaded neck l2 in which the opening II is centrally located. A cylindrical housing I3 is threaded into the neck I2, said housing including an external flange I 4 at an intermediate point. The housing I3 further includes an inturned liange I5 on its upper end.

A punch IB is mounted for vertical sliding movement in the housing I3 and operable in the opening II for engagement with the work, as at Il. The punch includes, at an intermediate point, a ange I8 which is engageable beneath the flange I5 of the housing I3. A coil spring I9 encircles the lower portion of the punch I6 in the housing I3 and is engaged beneath the flange I8 for returning said punch to raised position.

It is thought that the manner of using the device will be readily apparent from a consideration of the foregoing. Briefly, the graduated arm 6 is secured in the desired position in the groove 2 and the guide bar I is moved along an edge of the work I'I in the manner suggested in Figures 1 and 2 of the drawings. Thus, the arm 6 is positioned at one of the usual marks 20 on the work. The punch I6 is then struck with a hammer or other suitable tool for making the indentation precisely at the desired place in the work. The tool is then shifted to the next 1ocation on the work and the operation is repeated. Of course, the graduations on the arm 6 facilitate the adjustment of said arm. A washer 2l is provided between the arm 6 and the head of the thumb screw 8.

It is believed that the many advantages of a center punch constructed in accordance with the present invention will be readily understood, and although a preferred L embodiment. of v the, instrument is as illustrated arid describe@l it is to, be understood that Changes in the details of construction and in the combination and arrange; ment of parts may be resorted to which will fall within the scope of the invention as claimed` What is claimed is:

A center punch comprising 'a guideL bar slid;l

ably engageable with a piece of work; said bar having a transverse groove in one end portion, said bar including a thickened portion immediately adjacent the groove and having a substantially segmental recess therein, a graduated arm mounted on the bar and engaged in the groove when in operative position, said arm including a rounded end portion engageable in the recess when said arm is in inoperative position, said arm having al longitudinal. slotvtherein, a thumb screw threadedlyl mounted on the bar in the groove and'engaged in the slot for releasably securing the arm in operative position in said groove or in inoperative position in the recess, and a punch mounted on the free end portion of the` arm.

" GEORGE K. TOWNSEND, JR.

JACK K. TANIYAMA. 

